Certificate of correction



Aug. 30, 1932. s. RUMP 1,875,313

RESISTANCE DEPENDENT SELECTIVE RELAY Filed DBO. 1- l, 1929 Fig.7.

Inventor Sigurd Rump Attorney Patented Aug. 30, 1932 i, UNITED STATES PATENT OFFICE SIGURD BUMP, OF ZURICH, SWITZERLAND, ASSIGNOR TO AKTIENGESELLSCHAFT BROWN BOVERI & CIE'., OF'BAIDEN, SWITZERLAND, A JOINT-STOCK COMPANY OF SWITZERLAND RESISTANCE DEPENDENT SELECTIVE RELAY Application filed December 11, 1929, Serial No. 413,384, and in Germany December 19, 1928.

This invention relates to improvements in selective relays for protecting transmission lines from extensive short circuits and, particularly, to such relays as are responsive to conditions, such as ohmic resistance or impedance, impeding the flow of current.

The use of relays to disconnect a short circuited portion of a transmission line is well known. Such relays require both voltage and current transformers which are increasingly expensive as the voltage increases. It has been found, however, that the voltage element of a relay may be connected to the transmission line to be protected by usin a capacitance voltage transformer and t at the current element of such relay may be supplied by a voltage drop across either an ohmic or reactive resistance in parallel with a current transformer. When the voltage and current elements of a relay are connected, as

above indicated, to the transmission line, the

cost of the system is not only reduced by eliminating the voltage transformer and reducing the size of the current transformer but the interference of higherharmonics in the operation of the relay is also eliminated. It is, therefore, among the objects of the present invention to provide a selective relay, operable by resistance or impedance conditions in atransmission line to be protected, in which the relay voltage element is connected to the line by a capacitance voltage transformer.

Another object ofthe invention is to pro-v vide a selective protective relay, operated in dependence on the resistance or impedance of a line to be protected, in which the current member of the relay is supplied from the voltage drop across a resistance.

Another object of the invention is to provide a relay having an elcctro-static tripping-time determining element connected with a capacitance voltage transformer for supplying the voltage clement thereof and in which the current element is supplied with current by the voltage drop across a resistance.

Another object of the invention is to provide a selective protective relay, operable in dependence on. the resistance, or impedance conditions of a line to be protected, which relay is provided with an electro-static starting element connected with a capacitance voltage transformer and a current transformer supplying the tripping-time determining element of said relay.

Objects and advantages, other than those above set forth, will be apparent from the following description and the drawing, in which Figure 1 shows an embodiment of the present invention together with a diagrammatic showing of the connections of the relay to a transmission line to be protected.

Fig. 2 shows a modification of the starting or tripping system of a selective relay embodying the present invent-ion.

A selective relay, according to the present invention, comprises, in reality, three cooperating interdependent elements designated in the drawing at A, B and C, in which A is a starting or releasing element, B is a time delay element and C is a tripping-time control or determining element. The above three elements are arranged to form a compact single instrument and cooperate upon the occurrence of a short circuit in the line. The releasing of starting element A sets the time delay system B into operation which, in cooperation with the tripping-time determining clement C determines the tripping time of a circuit breaker 33 or similar protective device operable by the relay to disconnect the short circuited' portion of a transmission system.

The starting or releasing element A includes an electroanagnet Shaving a rotatable armature i to which is rigidly fastened a latching arm 6. lVhen a short circuit occurs in the portion of the transmission line to be protected by the relay, the change in the ohmic resistance or the impedance of the line acts on the energizing coil of the electromagnet of the starting element A to impart a rotary movement to the armature 4 and the latching arm 6 which then releases the time delay element B.

The time delay element B includes a weight 7 which is normally maintainedin the position shown in the drawing by arms 6 of element A. A rack Sis secured to the weight 7 to move therewith. The upper end of the rack 8 is formed as'a piston-like enlargement 9 movable within a cylinder 11 which retards a downward movement of rack 8.. A rack pinionj12, supported at 13 in an elongated slot, and which engages the rack 8, is afiixed to an arm 14. The pinion 12 is normally maintained in engagement with the rack 8 by a tension spring 16 which controls the opening or closing of contacts 17 in a circuit 18 for controlling the operation of a circuit breaker 33 or similar protective device.

The tripping-time determining element C includes a toothed member 19 pivoted at 21 together with a pointer or needle 22 coopera ing .with cylindrical segments 23 and 24:. The segments 23 and 24 function as voltage and current elements, respectively, of a relay and are connected with the transmission line by a grounded voltage transformer formed by condensers 27 and 28 and a grounded current transformer formed by an ohmic resistance 29 and a current transformer winding 31. The arm 14 of the time delay device B extends into such relation with the toothed member or segment 19 that a pin of the arm: may engage the member upon proper cooperative movement of the parts.

The needle 22, pivoted with the toothed seg ment 19, moves freely in a definite relation with the segments 23and 24. A potential difference corresponding to the voltage is produced between the segment 23 and the pointer 22; and a potential difference corresponding to the drop in the resistance 29 is produced between the segment 24: and the a pointer 22. Both segments producing an attracting force on the needle cause the same to move in the direction of the resultant of the two forces. 7

When the releasing element A of the relay is operated, the field of the electro-magnet 3 operates on the armature 1 to rotate the latchingarm 6 toward the left. As soon as the arm 6 has been rotated sufficiently to release the weight 7, the weight 7 begins to drop at a rate determined by the damping action of the piston 9 within the damping cylinder 11. The downward movement of the weight 7 with'the attached rack 8 rotates pinion 12 which in turn rotates arm 14 toward the right. l/Vhile the time delay element B of the relay has been operating as described immediately above, the time determining element C has likewise operated in that the pointer 22, together'with the toothed segmentlt), has been forced to take the direction'of the resultant of the forces on the segments 23 and 24:. The arm 14 continues to rotate in a clockwise direction until the pin thereon engages oneof the notches in the toothed member 19 which then blocks further rotation of the arm. Continued downward movement of the rack 8 forces the pinion out of contact therewith against the action of the tension spring 16 and causes contact to be made by the contact member 17 thereby closing the disconnection circuit 18 to cause operation of the circuit breaker 33 or similar protective device arranged in the portion of the line to which the relay is connected. 7

In the modified form of the invention shown in Fig. 2, the electro-magnetically' operated releasing element of the relay is replaced by an electro-static releasing system comprising an electro-static balance 32 which moves the arm 6 thereof toward the left when the'current is increased and when the voltage is decreased thereby releasing the weight 7 of the time delay element B so that the action as above described may take place. When an electro-statie system is used, the voltage and currentmay be supplied from the capacity voltage connection and from the current connection used to supply the current and voltage tothe electrostatic time determining element C as above described.

The present invention is not to be considered as restricted to the particular form of electro-static devices illustrated nor to the particular form of'the time delay system described, but it will be understood that any suitable electro-static systems may be used in place of those shown and that any suitable time delay device capable of cooperation with the starting and time determining elements may be used.

Although but a few embodiments of the invention have been illustratedand described, it will be'understood that various other embodiments are possible, and that various changes may be made without departing from the spirit of the invention or the scope of the appended claims. I

- I claim:

. 1. In a relay system for selectivelyprotecting electric transmission lines from the effects of extensive short clrcuits and the like,

a time delay element, means operable by said tion of a portion of a circuit connected therewlth, an electro-magnetically actuated element for starting operation of said time delay element, an electro-statically actuated element for determining the length of time required by said time delay element for actuating said means, and means for supplying potential to the said electro-magnetically actuated element and the said electro-statically actuated element from said circuit.

3. In a relay system for selectively protecting electric transmission lines from the effects of extensive short circuits and the like, a time delay element, means operable by said time delay element for controlling disconnection of a portion of a circuit connected therewith, an element for starting operation of said time delay element, an electro-statically actuated element for determining the length of time required by said time delay element for actuating said means, means for suppl ing energy from said circuit to the second said element and to one member of said electro-statically actuated element, and a capacitance transformer for supplying voltage to said electro-static time determining element.

4. In a relay system for selectively protecting electric circuits from the effects of extensive short circuits and the like, a time delay element, means operable by said time delay element for controlling disconnection of a portion of a circuit connected therewith, an element for starting operation of said time delay element, an electro-stat-ically actuated element for determining the length of time required by said time delay element for actuating said means, and connections for supplying energy to said electro-statically actuated element from a current supply means connected with said circuit as a potential drop.

5. In a relay system for selectively protecting electric circuits from the effects of extensive short circuits and the like, a time delay element, means operable by said time delay element for controlling disconnection of a portion of a circuit connected therewith, an element for starting operation of said time delay element, an electro-statically actuated element for determining the length of time required by said time delay element for actuating said means, and connections for supplying energy from said circuit to the said electro-statically actuated element as a potential drop comprising a current transformer and a resistance connected in parallel therewith.

6. In a relay system for selectively protecting electric circuits from the effects of extensive short circuits and the like, a time delay element, means operable by said time delay element for controlling disconnection of a portion of a circuit connected therewith, a system for starting operation of said time delay element, an electro-statically actuated element for determining the length of time required by said time delay element for actuating said means, and a capacitance transformer connection for supplying potential from said circuit to said electro-static time determining element and said element for starting operation of said time delay element.

7. In a relay system for selectively protecting electric circuits from the effects of shortcircuits and the like, a time-delay element, means operable by said time-delay element for controlling disconnection of a portion of a circuit connected therewith, an electrostatically actuated element for starting operation of said time-delay element, an electrostatically actuated element for determining the length of time required by said time-delay element for actuating said means, and connections for supplying potentials from said circuit to each of said electro-statically actuated elements.

8. In a relay system for selectively protecting electric circuits from the effects of shortcircuits and the like, a time-delay element, means operable by said delay element for controlling disconnection of a portion of a circuit connected therewith, an electro-statically actuated element for starting operation of said time-delay element, and an electrostatically actuated element for determining the length of time required by said timedelay element for actuating said means, each of the said electro-statically actuated elements having a plurality of potential responsive members, and connections for supplying potential to one of said potential members of each said electro-statically actuated elements comprising a current transformer winding and a resistance connected in parallel therewith.

9. In combination with a circuit to be protected from the effects of short circuits and the like, and a switch operable to effect connections and disconnections of a section thereof, of a relay comprising, means operable to cause said disconnection operation of said switch, a time-delay element movable to operate said means, an electro-statically actuated element operable to start said movement of said time-delay element, the said e'lect-ro-statically actuated element connected to said circuit to be actuated responsive to and in dependence upon a predetermined ratio of the voltage component to the current component thereof, and an electrostatically actuated element connected with said circuit to be movable responsive to and in extent in dependence upon the relative difference of the force of the voltage component and the force of the current component of said circuit to thereby control the time of operation of said means.

In testimony whereof I have hereunto subscribed my name this 22nd day of November,

SIGURD BUMP.

CERTIFICATE OF CORRECTION.

Patent No. 1,875,313. August 30, 1932.

SIGURD RUMP.

it is hereby certified that error appears in the printed specification of the fiiEGVC nurnhered patent requiring correction as follows: Pages '2 and 3, lines this, Hi, and 6, claims L 2 and 3 respectively, for "transmission lines" read "circuits"; page 3, line 58, claim 6, for "a system" read "an element"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the ease in the Patent Office.

Signed and sealed this 20th day of December A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

August 30, 1932..

Patent No. 1,875,313.

SIGU RD RUMP.

it is hereby certified that error appears in the printed specification of the aixove numbered patent requiring correction as fellows: Pages .2 and 3, lines 268, 121, and 6, claims i 2 and 3 respectively, for "transmission lines" read "circuits"; page 3, line 58, claim 6, for "a system" read "an element"; and that the said Letters Patent should be read with these corrections therein that the some may conform to the record of the ease in the Patent Office.

Signed and sealed this 20th day of December A. D. 1932.

M. J. Moore, Acting Commissioner of Patents.

(Seal) 

